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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

45410 results found.

  1. GRB 130504C: further Swift-XRT observations
  2. Konus-Wind observation of GRB 130504C
  3. GRB 130505B: MAXI/GSC detection
  4. GRB 130505A: optical observations
  5. GRB 130504C: Swift-XRT observations
  6. GRB 130504C: Fermi GBM detection
  7. GRB 130427A: optical observations in CrAO
  8. GRB 130502A: optical upper limit
  9. GRB 130505A: E_iso record retraction
  10. GRB 130427A: correction to GCN 14487
  11. GRB 130505A: correction to GCN 14575
  12. GRB 130505A: Swift-XRT refined Analysis
  13. GRB 130505A: Largest E_iso ever measured
  14. Konus-Wind observation of GRB 130505A
  15. GRB 130504C: Fermi-LAT detection of a burst
  16. Swift/UVOT observations of GRB130505A
  17. GRB 130505A: Xinglong TNT optical observations
  18. GRB 130505A; Weihai optical observations
  19. GRB 130505A: Enhanced Swift-XRT position
  20. GRB 130505A: MITSuME Okayama Optical Observation
  21. GRB 130505A - Gemini-N/GMOS redshift determination
  22. GRB 130505A: MAXI/GSC detection
  23. Konus-Wind observation of GRB 130504B
  24. GRB 130504A: IAC80 optical candidate
  25. GRB 130505A: Swift detection of a burst with optical afterglow
  26. GRB 130504A: MITSuME Okayama upper limits
  27. IPN Triangulation of GRB 130504B
  28. GRB 130504B: Fermi GBM detection
  29. GRB 130504A: Bassano Bresciano Observatory optical upper limit
  30. GRB 130504A: Enhanced XRT position
  31. GRB 130502B: Suzaku WAM observation of the prompt emission
  32. GRB 130504A: Swift/UVOT Upper Limits
  33. GRB 130502B: Swift-XRT refined Analysis
  34. GRB 130504A, Swift-BAT refined analysis
  35. Swift-XRT X-ray afterglow candidate for GRB 130504A (BAT trigger 555096)
  36. GRB 130502B: possible TNG counterpart
  37. Trigger 555096: Swift detection of a possible burst
  38. GRB 130502A: Swift-BAT refined analysis
  39. GRB 130427A: Non-observation of VHE emission with HAWC
  40. GRB130502A: MASTER-Net optical observations
  41. GRB 130502A: Swift-XRT refined Analysis
  42. IPN Triangulation of GRB 130502B
  43. GRB 130502A: Fermi GBM detection
  44. GRB 130502B: Swift/UVOT Upper Limits
  45. GRB 130502A: Swift/UVOT Upper Limits
  46. Konus-Wind observation of GRB 130502B
  47. GRB 130502B: P60 Observations
  48. GRB 130502B Swift-XRT observations
  49. GRB 130502A: RATIR Optical and NIR Observations
  50. GRB 130427A: Pan-STARRS 1 optical observations
  51. GRB 130418A: TNG NIR observations
  52. GRB 130502A: Enhanced Swift-XRT position
  53. GRB 130502A: OSN and IAC80 I-band observations
  54. GRB 130427A: MITSuME Ishigakijima Optical Observation after 5 days
  55. GRB 130502A: z-band observations from GTC
  56. GRB 130502B: Fermi LAT Detection
  57. GRB 130502A: TNG candidate counterpart
  58. GRB 130502B: Fermi GBM detection of a burst
  59. GRB 130502A: T100 Observations
  60. GRB 130502A: Swift detection of a burst
  61. GRB 130427A: Predictions about the occurrence of a supernova
  62. GRB 130427A: KAIT optical observations
  63. GRB 130425A: Suzaku WAM observation of the prompt emission
  64. GRB 130427A: SARA-N optical observations
  65. GRB 130427A: VLA 20 GHz detection
  66. GRB 130427A: ABT optical observations
  67. GRB 130427A: High-energy neutrino search
  68. GRB 130427A: GMRT radio detection
  69. GRB 130427A: Continued GMG optical observations
  70. GRB 130427A: Nishi-Harima Optical Spectroscopic Observations
  71. GRB 130427A: photo-z of possible SDSS host galaxy
  72. GRB 130427A: high energy gamma-ray detection by AGILE
  73. GRB 130427A: Continued RATIR Optical and NIR Observations
  74. GRB 130427A: MITSuME Ishigakijima Optical Observation after 2 days
  75. Swift-BAT trigger 554135 is noise
  76. GRB 130427A: Challis Observatory optical observations
  77. GRB 130427A: Continued Skynet/PROMPT Observations
  78. GRB 130427A: further GMG observations
  79. GRB 130427A: Fermi-LAT refined analysis
  80. GRB 130427A: SARA-N detection
  81. GRB 130427A: Continued RATIR Optical and NIR Observations
  82. GRB 130427A: CrAO RT-22 36 GHz observation
  83. GRB 130418A: Bassano Bresciano Observatory lightcurve analisis
  84. GRB 130427A in the Ep,i - Eiso plane
  85. GRB 130427A: Improved Swift-XRT analysis
  86. GRB 130425: MASTER-Net optical observations
  87. GRB 100728A: GROND host detection and X-shooter redshift
  88. GRB 130427B: MITSuME Ishigakijima upper limits
  89. GRB 130427A: MITSuME Okayama and Ishigakijima Optical Observation after 1 day
  90. GRB 130427A: Skynet/PROMPT Observations
  91. GRB 130427B: RATIR Optical and NIR Observations
  92. GRB 130427A: Nishi-Harima NIR Observations
  93. GRB 130427A: CARMA 3mm observations
  94. GRB 130427B: Tentative VLT/X-shooter redshift
  95. GRB 130427A : Xinglong TNT optical observation
  96. GRB 130427A: VLT/X-shooter redshift confirmation
  97. GRB 130427A optical time series
  98. GRB 130427A, Optical Observations
  99. Konus-Wind observation of GRB 130427A
  100. GRB 130427A: Kanata/HOWPol optical imaging polarimetry

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